Ah, that is great, thank you very much! That is very understandable. So when the level of integrity is the same of two programs one can transfer data from one to the other. But, sorry, I am missing anything obviously. I now have the same level of integrity but it still does not work:https://i.imgur.com/8aW6wf6.png

FirefoxPortable.exe which is what you should be starting FF with (otherwise you would be running FF directly, hence, not portable), is running High.But FF itself (firefox.exe) are running at Medium (or less).

So when you drag from "FF" (firefox.exe), Medium, into FreeCommander, High, that won't work.

(FirefoxPortable.exe is only a "stub", that runs firefox.exe. That FirefoxPortable.exe is running High, does not mean that firefox.exe itself is also high, in this case.)